The primary purpose of early detection of autism spectrum disorders is to prevent or mitigate the full onset of autism and its associated severe disabilities. Early detection science requires that early treatment science develop in parallel, so that tested treatments are ready for infants identified by early detection. There are currently no empirically validated treatments for children with ASD under 2 years of age, and, to our knowledge, no treatment models that target autism-specific symptoms for infants 6-11 months of age. The planned project will address the need for autism-specific interventions for the 6-11 month age period. The project's overall goal is to develop and pilot test a manualized, parent-delivered intervention for symptomatic infants'ages 6-11 months of age at high risk for autism that will reduce atypical behaviors and developmental delays and increase developmental rates, thus lessening or preventing the full expression of autism. The intervention will target five behaviors occurring in infants who show abnormal behaviors in the first year of life and later develop autism, as documented by prospective and retrospective evidence. These include: (1) visual fixations on objects;(2) abnormal repetitive behaviors;(3) lack of intentional communicative acts;(4) lack of age- appropriate, phonemic development;and (5) lack of coordination of gaze, affect, and voice in reciprocal, turn-taking interactions. The project will: Develop a parent-delivered intervention for 6-11 month olds, defined in treatment manuals and fidelity measures that targets general delays and the five target symptoms: (1) visual fixations on objects; (2) abnormal repetitive behaviors;(3) lack of intentional communicative acts;(4) lack of age- appropriate phonemic development;and (5) lack of coordination of gaze, affect, and voice in reciprocal, turn-taking interactions, Determine frequencies and characteristics of the 5 target symptoms in typical infants 6-11 months of age from research reviews and from an observational study from existing data in our current autism infant sibling study; 3. Examine and treatment efficacy for 5 symptomatic infant siblings ages 6-11 months and their parents in a multiple baseline across subjects and across behaviors design;4. Publish efficacy data and prepare a larger grant submission for a controlled group study. PUBLIC HEALTH RELEVANCE: Current studies of the earliest symptoms of autism spectrum disorders are opening up the possibility of being able to identify autism risk in infants before their first birthday, allowing for early identification and intervention, which currently there are no interventions developed or tested on infants this young. The goal of this project is to develop and test an intervention for 6-11 month old infants at risk for ASD, as well as, showing some symptoms, through intervention techniques delivered by parents/caretakers during their daily caretaking activities with the infant and taught to parents during weekly individual parent-child play sessions. The intervention will be piloted with eight at risk and symptomatic infant siblings of an older child with autism, whose focus will be on using positive techniques to increase child gaze, intentional communicative vocalizations, shared toy play, emotion sharing, and early stages of joint attention.